#include <iostream>
#include <stdio.h>
#include <string.h>
//#include <math.h>
using namespace std;

int main()
{
    int n, m, k;
    int from[14], to[14], i;
    scanf("%d%d%d", &n, &m, &k);
    for (i=1; i<=k; ++i)
        scanf("%d", from+i);
    for (i=1; i<=k; ++i)
        scanf("%d", to+i);
    int ans=0;
    for (i=1; i<=k; ++i)
        if (from[i] > to[i])
                ans += from[i] - to[i];
    printf("%d\n", ans);
    return 0;
}    


